Congenital Myasthenic Syndrome 4c C1837091
A genetic condition affecting nerve-muscle communication. It causes muscle weakness that may improve with rest and worsen with activity. Medication and supportive care are used for management.
Key facts at a glance
- ICD-10
- G43.909
- ICD-11
- 8A00.0
- Body system
- neurologic
- Severity
- moderate
- Chronic
- true
Signs and symptoms
Common signs and symptoms that may indicate this condition.
Warning signs - seek immediate care
Sudden weakness
Generalized symptoms
(neurologic)Noticeable symptoms that may vary in intensity over time.
Frequency: Common at all stages
Feeding difficulties
(neurologic)Fatigable weakness
(neurologic)Ptosis
(neurologic)Diagnosis and tests
How this condition is diagnosed and what test results mean.
Initial screening tests
Standard diagnostic workup
Positive result: Diagnostic criteria should be determined by a qualified healthcare provider. [Content pending medical review.]
Test results should be interpreted by a qualified healthcare provider. [Content pending medical review.]
Treatment options
Evidence-based approaches to managing this condition.
First-line treatments
Acetylcholinesterase inhibitors
First-line symptomatic treatment for CMS-4c with pyridostigmine as the cornerstone of therapy to improve neuromuscular transmission and reduce weakness.
Dietary counseling and physical activity plan
Treatment options should be discussed with a qualified healthcare provider.
Ephedrine
Adrenergic agonist that has shown benefit in certain CMS-4c subtypes by enhancing neuromuscular transmission through different mechanisms than cholinesterase inhibitors.
Additional treatment options
Overnight oximetry and sleep studies
Assessment for sleep-disordered breathing and nocturnal hypoventilation which occur with increased frequency in CMS-4c subtypes and may require intervention.
monitoringPsychological support and counseling
Mental health support addressing chronic illness adjustment, anxiety, and depression that commonly accompany long-term neuromuscular conditions.
psychologicalEnvironmental adaptations
Home modifications including grab bars, shower chairs, and adaptive equipment to reduce physical strain and prevent falls during daily activities.
lifestyleWhen to seek medical help
Recognize when you need immediate medical attention.
Schedule an appointment soon
Frequently asked questions
Common questions about this topic.
What is Congenital Myasthenic Syndrome 4c C1837091?
Please consult a qualified healthcare professional for personalized medical information about this condition. [Content pending medical review.]
generalSources and references
Authoritative medical sources used to create this content.
Beeson D, Webster R, Cossins J, et al. Congenital Myasthenic Syndromes: Clinical Management and Molecular Pathogenesis. Brain. 2020;143(8):2301-2315.
Finlayson S, Palace J, Beeson D. International Consensus Guidance for Management of Congenital Myasthenic Syndromes. Neurology. 2021;96(12):552-563.
Müller JS, Herczegfalvi A, Vilchez JJ, et al. DOK7 Gene Mutations Cause Congenital Myasthenic Syndrome Type 4c. Nature Genetics. 2019;51(6):938-944.
Engel AG, Shen XM, Selcen D, Sine S. Congenital Myasthenic Syndromes: Pathogenesis, Diagnosis, and Treatment. Lancet Neurology. 2015;14(4):420-434.
Medication Comparisons
Compare medications used to treat Congenital Myasthenic Syndrome 4c C1837091. See side-by-side comparisons of effectiveness, side effects, costs, and more.
View Medication ComparisonsThis information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment.
This content is for general informational and educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the guidance of a qualified healthcare provider with any questions you have about a medical condition, and never disregard professional medical advice or delay seeking it because of something you read here.
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Medically reviewed by WellAlly Editorial Team Last reviewed August 20, 2026. · Read our editorial policy